In recent years, image information is handled as digital data, and, for the purpose of transmission and accumulation of the information having high-efficiency at that time, devices are widely used which compress and code images by employing a coding system compressing image information through an orthogonal transform such as a discrete cosine transform and motion compression by using the redundancy that is unique to the image information. As examples of such a coding system, there are MPEG (Moving Picture Experts Group), H.264, MPEG-4 Part 10 (Advanced Video Coding, hereinafter, referred to as AVC), and the like.
Currently, for the purpose of further improving the coding efficiency to be higher than that of H.264/AVC, standardization of a coding system called high efficiency video coding (HEVC) has been progressed by a joint collaboration team—video coding (JCTVC) that is a joint standardization organization of the ITU-T and the ISO/IEC. In addition, as an extension thereof, standardization of coding of a multi-viewpoint image has been progressed in parallel therewith, and as a draft for coding a multi-viewpoint image, Non-Patent Document 1 has been issued.
Meanwhile, a reference list that is a list in which candidates for a reference image used for decoding a B picture are aligned in a preferential order is sequentially generated from the start of reference images aligned in a preferential order in a temporal list that is a temporary list.
In Non-Patent Document 1, the temporal list is generated such that, after reference images disposed in the time direction, reference images disposed in the view direction are arranged. Thus, in order to raise the preferential order of the reference images disposed in the view direction within the temporal list, unless a reference list command is used, it is difficult to arrange the reference images disposed in the view direction in the reference list, and accordingly, it is difficult to refer to the reference images disposed in the view direction.
Thus, in Non-Patent Document 2, it is proposed to transmit information designating a position at which a reference image disposed in the view direction is inserted among a plurality of reference images disposed in the time direction using a slice header when a temporal list is generated. Accordingly, in consideration of a view-direction correlation, a reference image disposed in the view direction can be inserted at a preferable position in the temporal list.